Related papers: Transversity distributions from difference asymmet…
The study of transverse spin and transverse momentum effects is an important part of the scientific program of COMPASS, a fixed target experiment at the CERN SPS taking data since 2002. The studies are carried on by measuring the hadrons…
The COMPASS Collaboration at CERN has measured the transverse spin azimuthal asymmetry of charged hadrons produced in semi-inclusive deep inelastic scattering using a 160 GeV positive muon beam and a transversely polarised NH_3 target. The…
We summarize the latest achievements about the extraction of the transversity parton distribution and proton tensor charge based on an analysis of pion-pair production in deep-inelastic scattering off transversely polarized targets.…
Information on the Sivers distribution and the Collins fragmentation functions and their transverse momentum dependence is mainly based on fitting single spin asymmetry data from semi-inclusive deep inelastic scattering (SIDIS). Independent…
Previously we showed that, based only on C and SU(2) invariance, the difference cross sections of hadrons with opposite charge in SIDIS e+N\to l+h+X is expressed solely in terms of the valence-quark densities and certain non-singlet…
COMPASS is a fixed-target high energy physics experiment at the SPS at CERN \cite{Abbon:2007pq}. One of the important objectives of the experiment is the exploration of the transverse spin structure of the nucleon via spin dependent…
Polarised Semi-Inclusive Deep Inelastic Scattering (SIDIS) processes allow to study Transverse Momentum Dependent partonic distributions (TMDs), which reveal a non trivial three dimensional internal structure of the hadrons in momentum…
Some general remarks on parton transverse spin distributions and transverse motions are presented. The issue of accessing experimental information on the transversity distributions h_1^q is discussed. In particular direct information could…
The role of hadronization mechanism in polarization phenomena in semi inclusive deep inelastic scattering (SIDIS) and a purity method for extraction of polarized distribution functions are discussed. According to the Monte Carlo (MC) event…
We present preliminary results for an updated extraction of the transversity parton distribution based on the analysis of pion-pair production in deep-inelastic scattering off transversely polarized targets in collinear factorization. Data…
First measurements of azimuthal asymmetries in hadron-pair production in deep-inelastic scattering of muons on transversely polarised ^6LiD (deuteron) and NH_3 (proton) targets are presented. The data were taken in the years 2002-2004 and…
The study of $\Lambda$ polarization in Semi-Inclusive Deep Inelastic Scattering (SIDIS) with a transversely polarized target has often been suggested as a privileged way to access transversity, as the initial quark polarization can be…
The aim of this Thesis is to contribute to the understanding of the nucleon structure through the study of two observables accessible in Semi-Inclusive Deep Inelastic Scattering (SIDIS) of high energy leptons off unpolarized protons: the…
We present a point-by-point determination of the valence transversity distributions from two different types of processes: single-hadron production and dihadron production, both in semi-inclusive deep inelastic scattering and e+e-…
A set of measurements of azimuthal asymmetries in the production of pairs of identified hadrons in deep-inelastic scattering of muons on transversely polarised $^6$LiD (deuteron) and NH$_3$ (proton) targets is presented. All available data…
In 2016 and 2017, the COMPASS Collaboration at CERN collected a large sample of DIS events with a longitudinally polarized 160 GeV/c muon beam scattering off a liquid hydrogen target. Part of the collected data has been analyzed to extract…
COMPASS is a fixed target experiment at the CERN SPS, with a rich physics program focused on nucleon spin structure and on hadron spectroscopy. One of the main goals of the spin program is the measurement of the transverse spin distribution…
Transversity distribution is one of the three fundamental parton distributions that completely describe polarized spin 1/2 nucleon. Its chiral odd nature prevented for many years its experimental exploration, however presently we have…
Using a model calculation of dihadron fragmentation functions, we fit the spin asymmetry recently extracted by HERMES for the semi-inclusive pion pair production in deep-inelastic scattering on a transversely polarized proton target. By…
We discuss a possible explanation of the 25 year old mystery of the large transverse spin asymmetries found in many semi-inclusive hadron-hadron reactions. We obtain the first reliable information about the transverse polarized quark…